1. Balancing Types Predicting
Equations
Balancing
Types
Predicting

2. Table of Contents
6.1 Conservation of Mass and Balancing Equations Slides 4 & 5
6.2 Types of Reactions Slides
6.3 Predicting Equations Slides

3. Law of Conservation of Mass
8D Use the law of conservation of mass to write and balance chemical equations.

4. Define the Law of Conservation of Mass
Matter cannot be created nor destroyed.
In a chemical reaction, the mass of the products equals the mass of the reactants.
The number of atoms in the reactant side must equal the number of atoms in the product side.
No new elements appear.
No elements disappear.

5. Balancing Equations 6 6 6 CO2 + H20  C6H1206+ O2 C 1 6 C 6 O 3 18 O 8
Step 1: Write the equation
Step 2: Draw a line through the middle of the equation.
Step 3: Write down the reactants and products. Plus how many atoms you have of each.
Step 4: Look for numbers that are not the same and balance to the highest number.
Step 5: Using multiplication multiply the small number by a number that will give you the same number on the opposite side.
Step 6: This sometimes will change your coefficient please just adjust.
Step 7: When you are done look at both sides and see if your numbers match, if they don’t start the process again.
CO H  C6H O2 6 18 12
C 1
O 3
H 2
C 6
O 8
H 12 18

6. Your Turn
Get into groups of three and complete the balancing equations worksheet provided by your teacher.

7. Types of Reactions

8. Na + Cl → NaCl Synthesis Reaction
In a synthesis reaction, two or more substances combine to form one new substance.
Na + Cl → NaCl

9. Decomposition Reaction
This is a reaction where many substances will break up, or decompose into simpler substances when energy is supplied. This energy may come from heat, light, mechanical shock, or electricity.
Pb(OH)2(s) → PbO(s) + H2O(g)

10. Single Displacement Reactions
In this type of reaction, one element displaces(replace) another element in a compound. Example:
Cl2(g) + 2KBr(aq) → 2KCl(aq) + Br2(l)
Chlorine displaces bromine from potassium bromide .

11. Double Discplacement Reaction
Double Replacement Reaction occurs when the positive and negative portions of two compounds are interchanged. Example:
PbCl2(s) + Li2SO4(aq) → PbSO4(s) + 2LiCl(aq)
In this reaction the chlorine and sulfate exchanged places.

12. hydrocarbon + oxygen → carbon dioxide + water
Combustion
Almost all organic compound and some inorganic compounds will burn in air. Many will ignite quite readily and are considered flammable. The general form for combustion reactions is:
hydrocarbon + oxygen → carbon dioxide + water
CH → CO2 + 2H20

13. Classify each of the following rxns.
1. CuO + H2 → Cu + H2O
2. 2H2O2 → 2H2O + O2
3. 2Ag + S → Ag2S
4. C4H8 + 6O2 → 4CO2 + 4H2O
5. HCl + NaOH → H2O + NaCl
Single displacement
Decomposition
Synthesis
Combustion
Double displacement

15. Predicting Products

16. Predicting Products Example
Aluminum reacts with zinc oxide to produce aluminum oxide and zinc.
Step 1 substitute symbols and formulas for name.
Al + ZnO →
Step 2 balance the equation.
Al + ZnO → Al2O3 + Zn
Step 3 What type of reaction is it?
Single Replacement
Al2O3 + Zn 2 3 3

17. Predict the products formed in each of the following reactions
1. The single displacement reaction between aluminum and copper (II) nitrate.
2. The synthesis of mercury (II) oxide from its elements.
3. The double displacement reaction of sulfuric acid, and potassium hydroxide.
4. The combustion of cyclopentane.
5. The decomposition of Magnesium chlorate yields Magnesium chloride plus oxygen.
1.) 2Al+3Cu(NO3)2 -> 2Al(NO3)3+3Cu
2.) 2Hg+O2 -> 2HgO
3.) H2SO4+2KOH -> K2SO4+2H2O
4.) 2C5H10+15O2 -> 10CO2+10H2O
5.) Mg(ClO3)2 -> MgCl2+3O2